#include <set>
#include <iostream>
#include <algorithm>
#include <cstdlib>

using namespace std;

int find(int k)
{
    double Sn = 0.0;
    double n = 1.0;
    while (Sn < k)
    {
        Sn += (1.0 / n);
        n += 1.0;
    }
    return n - 1;
}

int main(int argc, char const *argv[])
{
    auto k = 0;
    cin >> k;
    auto n = find(k);
    cout << n << endl;
    return 0;
}